<?php
/**
 * 观影评价与讨论（v9，模型照搬 MovieLog 的 lib/reviews.php）。
 *
 * 数据模型：
 *   movie_reviews          一部电影 × 一个账号 至多一条（rating 1-10 + 正文 + 感受）
 *   movie_review_comments  挂在评价下的讨论，两级平铺：
 *                          parent_id 为空 → 顶层评论；非空 → 指向「所属顶层评论」的 id
 *                          （回复的回复会被规范化到顶层，页面永远只有两层），
 *                          reply_to_person_id 记「被回复的人」，显示「回复 @谁」。
 *
 * 评价人是「登录账号背后的人」（persons.id），与同行观影人无关：
 * 没一起去看的人只要有账号，也能打分、写评价并参与讨论。
 *
 * 感受只存 key（如 warm / sad），emoji 与文案统一在 CATALOG 里维护，
 * 改文案 / 换 emoji 都不需要动数据。emoji 只选 Emoji 11.0（2018）及以前的老码位
 * —— 更新的字形在旧系统字体里会显示成方框。
 */

declare(strict_types=1);

namespace App;

final class MovieReview
{
    public const CONTENT_MAX  = 5000;   // 评价正文最大字数（UTF-8 字符）
    public const COMMENT_MAX  = 1000;   // 评论正文最大字数
    public const FEELING_MAX  = 6;      // 一条评价/评论最多能选几种感受

    /** 观后感受目录：key => [emoji, 中文标签] */
    public const CATALOG = [
        'happy'      => ['emoji' => '😄', 'label' => '开心'],
        'moved'      => ['emoji' => '💖', 'label' => '感动'],
        'warm'       => ['emoji' => '🥰', 'label' => '温暖'],
        'excited'    => ['emoji' => '🤩', 'label' => '激动'],
        'thoughtful' => ['emoji' => '🤔', 'label' => '深思'],
        'tense'      => ['emoji' => '😰', 'label' => '紧张'],
        'scared'     => ['emoji' => '😨', 'label' => '恐惧'],
        'surprised'  => ['emoji' => '😲', 'label' => '震惊'],
        'sad'        => ['emoji' => '😢', 'label' => '难受'],
        'angry'      => ['emoji' => '😠', 'label' => '气愤'],
        'bored'      => ['emoji' => '😴', 'label' => '无聊'],
        'confused'   => ['emoji' => '😵', 'label' => '困惑'],
    ];

    /** v8 时代 movie_details.feelings 存的中文标签 → 目录 key（迁移用） */
    private const LABEL_TO_KEY = [
        '温暖' => 'warm',   '激动' => 'excited', '欢乐' => 'happy',
        '深思' => 'thoughtful', '伤感' => 'sad', '震撼' => 'surprised',
        '治愈' => 'moved',  '无聊' => 'bored',   '开心' => 'happy',
        '感动' => 'moved',  '紧张' => 'tense',   '恐惧' => 'scared',
        '震惊' => 'surprised', '难受' => 'sad',  '气愤' => 'angry',
        '困惑' => 'confused',
    ];

    /** @return array<int,string> 1-10 分各给一句词（打分实时提示 / title 用） */
    public static function ratingWords(): array
    {
        return array_map(static fn($r) => self::ratingWord($r), range(1, 10));
    }

    public static function ratingWord(int $rating): string
    {
        return match (true) {
            $rating <= 2 => '很失望',
            $rating <= 4 => '不太行',
            $rating <= 6 => '还行',
            $rating <= 8 => '不错',
            default      => '很棒',
        };
    }

    /** 把表单提交（数组）或库里取出的数组整理成合法 key 列表：过滤、去重、截断、按目录顺序 */
    public static function normalizeFeelings(array $raw): array
    {
        $picked = [];
        foreach ($raw as $key) {
            $key = is_string($key) ? trim($key) : '';
            if ($key !== '' && isset(self::CATALOG[$key]) && !in_array($key, $picked, true)) {
                $picked[] = $key;
            }
        }
        $ordered = [];
        foreach (array_keys(self::CATALOG) as $key) {
            if (in_array($key, $picked, true)) {
                $ordered[] = $key;
            }
        }
        return array_slice($ordered, 0, self::FEELING_MAX);
    }

    /** 库里 feelings JSON → 合法 key 列表 */
    public static function parseFeelings(?string $json): array
    {
        if ($json === null || $json === '') {
            return [];
        }
        $keys = json_decode($json, true);
        return is_array($keys) ? self::normalizeFeelings($keys) : [];
    }

    public static function feelingsToJson(array $keys): string
    {
        return json_encode(array_values($keys), JSON_UNESCAPED_UNICODE);
    }

    /** v8 迁移用：旧中文标签 JSON → 新 key JSON（认不出的丢掉） */
    public static function labelsToKeysJson(string $json): ?string
    {
        if (trim($json) === '') {
            return null;
        }
        $labels = json_decode($json, true);
        if (!is_array($labels)) {
            return null;
        }
        $keys = [];
        foreach ($labels as $label) {
            $k = self::LABEL_TO_KEY[trim((string)$label)] ?? null;
            if ($k !== null && !in_array($k, $keys, true)) {
                $keys[] = $k;
            }
        }
        return $keys ? self::feelingsToJson(self::normalizeFeelings($keys)) : null;
    }

    // ---------------- 读取 ----------------

    /** 某部电影的全部评价（新在前），讨论按两级结构挂好 */
    public static function forEvent(int $eventId): array
    {
        $st = Database::get()->prepare(
            'SELECT r.*, p.name AS person_name, p.avatar AS person_avatar
             FROM movie_reviews r JOIN persons p ON p.id = r.person_id
             WHERE r.event_id = ?
             ORDER BY r.created_at DESC, r.id DESC'
        );
        $st->execute([$eventId]);
        $reviews = $st->fetchAll();
        foreach ($reviews as &$rv) {
            $rv['feelings'] = self::parseFeelings($rv['feelings']);
        }
        unset($rv);
        self::attachComments($reviews);
        return $reviews;
    }

    /** 给一批评价挂上 comments（一次查询）；两级平铺：回复全部归到所属顶层评论下 */
    private static function attachComments(array &$reviews): void
    {
        if (!$reviews) {
            return;
        }
        $ids = array_values(array_filter(array_column($reviews, 'id'), static fn($v) => (int)$v > 0));
        if (!$ids) {
            return;
        }
        $ph = implode(',', array_fill(0, count($ids), '?'));
        $st = Database::get()->prepare(
            "SELECT c.*, p.name AS person_name, p.avatar AS person_avatar,
                    rp.name AS reply_to_name
             FROM movie_review_comments c
             JOIN persons p ON p.id = c.person_id
             LEFT JOIN persons rp ON rp.id = c.reply_to_person_id
             WHERE c.review_id IN ($ph)
             ORDER BY c.created_at ASC, c.id ASC"
        );
        $st->execute($ids);

        $byId = [];
        foreach ($st->fetchAll() as $row) {
            $row['feelings']  = self::parseFeelings($row['feelings']);
            $row['parent_id'] = ($row['parent_id'] === null || (int)$row['parent_id'] <= 0)
                ? null : (int)$row['parent_id'];
            $byId[(int)$row['id']] = $row;
        }

        // 顶层评论按评价分桶（保持时间顺序）
        $grouped = [];   // review_id => [ ['comment'=>…, 'replies'=>[…]], … ]
        $index   = [];   // review_id => [顶层评论 id => 下标]
        foreach ($byId as $row) {
            if ($row['parent_id'] !== null) {
                continue;
            }
            $rvId = (int)$row['review_id'];
            $grouped[$rvId][] = ['comment' => $row, 'replies' => []];
            $index[$rvId][(int)$row['id']] = count($grouped[$rvId]) - 1;
        }
        // 挂回复：沿 parent 链向上找所属顶层评论（容忍手工改坏的数据，最多 20 步防成环）
        foreach ($byId as $row) {
            if ($row['parent_id'] === null) {
                continue;
            }
            $rvId = (int)$row['review_id'];
            $root = (int)$row['parent_id'];
            for ($i = 0; $i < 20 && isset($byId[$root]) && $byId[$root]['parent_id'] !== null; $i++) {
                $root = (int)$byId[$root]['parent_id'];
            }
            if (isset($index[$rvId][$root])) {
                $grouped[$rvId][$index[$rvId][$root]]['replies'][] = $row;
            }
            // 所属顶层已被删的回复直接丢掉，不让它变成挂在评价上的孤儿
        }

        foreach ($reviews as &$rv) {
            $rv['comments'] = $grouped[(int)$rv['id']] ?? [];
        }
        unset($rv);
    }

    /** 评分概况：['count' => n, 'avg' => 7.5]；没人评价时 avg 为 null（展示别显示 0 分） */
    public static function stats(int $eventId): array
    {
        $st = Database::get()->prepare(
            'SELECT COUNT(*) AS c, AVG(rating) AS a FROM movie_reviews WHERE event_id = ?'
        );
        $st->execute([$eventId]);
        $row  = $st->fetch();
        $n    = (int)($row['c'] ?? 0);
        return ['count' => $n, 'avg' => $n > 0 ? round((float)$row['a'], 1) : null];
    }

    /** 给瀑布流的行批量挂上评分概况（一次查询） */
    public static function attachStats(array &$rows): void
    {
        if (!$rows) {
            return;
        }
        $ids = array_values(array_unique(array_filter(
            array_column($rows, 'id'),
            static fn($v) => (int)$v > 0
        )));
        if (!$ids) {
            return;
        }
        $ph = implode(',', array_fill(0, count($ids), '?'));
        $st = Database::get()->prepare(
            "SELECT event_id, COUNT(*) AS c, AVG(rating) AS a
             FROM movie_reviews WHERE event_id IN ($ph) GROUP BY event_id"
        );
        $st->execute($ids);
        $map = [];
        foreach ($st->fetchAll() as $row) {
            $map[(int)$row['event_id']] = [
                'count' => (int)$row['c'],
                'avg'   => round((float)$row['a'], 1),
            ];
        }
        foreach ($rows as &$r) {
            $r['review_count'] = $map[(int)$r['id']]['count'] ?? 0;
            $r['review_avg']   = $map[(int)$r['id']]['avg'] ?? null;
        }
        unset($r);
    }

    /** 当前账号在这部电影上的评价（没有则 null） */
    public static function mine(int $eventId, int $personId): ?array
    {
        if ($personId <= 0) {
            return null;
        }
        $st = Database::get()->prepare(
            'SELECT * FROM movie_reviews WHERE event_id = ? AND person_id = ?'
        );
        $st->execute([$eventId, $personId]);
        $row = $st->fetch();
        if ($row) {
            $row['feelings'] = self::parseFeelings($row['feelings']);
        }
        return $row ?: null;
    }

    public static function reviewById(int $reviewId): ?array
    {
        $st = Database::get()->prepare('SELECT * FROM movie_reviews WHERE id = ?');
        $st->execute([$reviewId]);
        return $st->fetch() ?: null;
    }

    public static function commentById(int $commentId): ?array
    {
        if ($commentId <= 0) {
            return null;
        }
        $st = Database::get()->prepare('SELECT * FROM movie_review_comments WHERE id = ?');
        $st->execute([$commentId]);
        return $st->fetch() ?: null;
    }

    // ---------------- 写入 ----------------

    /**
     * 发表/修改评价：每人对每部电影只有一条，已有则更新。
     * 校验：rating 1-10、正文非空未超长。成功返回 true，失败返回错误文案。
     */
    public static function save(int $eventId, int $familyId, int $personId, int $rating,
                                string $content, array $feelings, bool $isUpdate): string
    {
        if ($rating < 1 || $rating > 10) {
            return '请先选一个 1-10 的评分';
        }
        $content = trim($content);
        if ($content === '') {
            return '评价内容不能为空';
        }
        if (mb_strlen($content, 'UTF-8') > self::CONTENT_MAX) {
            return '评价内容太长了（最多 ' . self::CONTENT_MAX . ' 字）';
        }
        $feel = self::feelingsToJson(self::normalizeFeelings($feelings));
        $db   = Database::get();
        if ($isUpdate) {
            $db->prepare(
                'UPDATE movie_reviews SET rating = ?, content = ?, feelings = ? WHERE id = ?'
            )->execute([$rating, $content, $feel, (int)self::mine($eventId, $personId)['id']]);
        } else {
            $db->prepare(
                'INSERT INTO movie_reviews (family_id, event_id, person_id, rating, content, feelings)
                 VALUES (?, ?, ?, ?, ?, ?)'
            )->execute([$familyId, $eventId, $personId, $rating, $content, $feel]);
        }
        return '';
    }

    /** 删除自己的评价（下面的讨论随外键级联一起删）。只能删自己的。 */
    public static function deleteMine(int $reviewId, int $personId): bool
    {
        $st = Database::get()->prepare(
            'DELETE FROM movie_reviews WHERE id = ? AND person_id = ?'
        );
        $st->execute([$reviewId, $personId]);
        return $st->rowCount() > 0;
    }

    /**
     * 在一条评价下评论，或回复某条评论。parent_id=0 → 顶层；>0 → 回复那条。
     * 回复的回复规范化到同一条顶层评论之下（库里 parent_id 永远指向顶层）。
     * 成功返回新评论 id，失败返回错误文案。
     */
    public static function addComment(int $reviewId, int $personId, string $content,
                                      array $feelings, int $parentId): int|string
    {
        $content = trim($content);
        if ($content === '') {
            return $parentId > 0 ? '回复内容不能为空' : '评论内容不能为空';
        }
        if (mb_strlen($content, 'UTF-8') > self::COMMENT_MAX) {
            return ($parentId > 0 ? '回复' : '评论') . '内容太长了（最多 ' . self::COMMENT_MAX . ' 字）';
        }
        $review = self::reviewById($reviewId);
        if (!$review) {
            return '这条评价不存在';
        }

        $parent  = null;
        $replyTo = null;
        if ($parentId > 0) {
            $parent = self::commentById($parentId);
            // 只能回复「同一条评价下」的评论，防止拿别的评价的 comment_id 跨过去
            if (!$parent || (int)$parent['review_id'] !== $reviewId) {
                return '要回复的那条评论不存在';
            }
            $replyTo  = (int)$parent['person_id'];
            if ($parent['parent_id'] !== null && (int)$parent['parent_id'] > 0) {
                $parentId = (int)$parent['parent_id'];   // 回复的回复挂到顶层
            }
        }

        $db = Database::get();
        $db->prepare(
            'INSERT INTO movie_review_comments
             (review_id, person_id, parent_id, reply_to_person_id, content, feelings)
             VALUES (?, ?, ?, ?, ?, ?)'
        )->execute([
            $reviewId, $personId,
            $parentId > 0 ? $parentId : null,
            $replyTo,
            $content,
            self::feelingsToJson(self::normalizeFeelings($feelings)),
        ]);
        return (int)$db->lastInsertId();
    }

    /** 删除自己的评论；删顶层时连回复一起删（回复只存在于顶层之下，留着就是孤儿） */
    public static function deleteComment(int $commentId, int $personId): bool
    {
        $db = Database::get();
        $st = $db->prepare(
            'DELETE FROM movie_review_comments WHERE id = ? AND person_id = ?'
        );
        $st->execute([$commentId, $personId]);
        if ($st->rowCount() <= 0) {
            return false;
        }
        $db->prepare('DELETE FROM movie_review_comments WHERE parent_id = ?')
           ->execute([$commentId]);
        return true;
    }
}